9 research outputs found

    Deregulated expression of CD40 ligand in HTLV-I infection: Distinct mechanisms of downregulation in HTLV-I-transformed cell lines and ATL patients

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    AbstractHTLV-I infection is associated with the development of adult T cell leukemia (ATL) and the neuroinflammatory disease HAM/TSP. There are quantitative and qualitative differences in the antiviral cytotoxic T cell (CTL) response in ATL and HAM/TSP although the underlying mechanisms are unclear. Here, we demonstrate that the HTLV-I Tax trans-activating protein is a transcriptional activator of CD40 ligand (CD40L), a critical regulator of dendritic cell maturation and adaptive immunity. Tax activates CD40L expression via a cyclosporin A insensitive pathway that is also independent of NF-κB. Although Tax upregulates CD40L gene expression, CD40L expression is absent in Tax-expressing HTLV-I-transformed cell lines via an epigenetic mechanism involving methylation. T lymphocytes cultured ex vivo from ATL patients, but not HAM/TSP or normal controls, exhibit a potent block in the induction of CD40L, but not CD69. However, the CD40L gene is not silenced by methylation in ATL patients, thus CD40L is downregulated by distinct mechanisms in HTLV-I-transformed cell lines and ATL patients

    Wireless, Battery-Free Implants for Electrochemical Catecholamine Sensing and Optogenetic Stimulation

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    Neurotransmitters and neuromodulators mediate communication between neurons and other cell types; knowledge of release dynamics is critical to understanding their physiological role in normal and pathological brain function. Investigation into transient neurotransmitter dynamics has largely been hindered due to electrical and material requirements for electrochemical stimulation and recording. Current systems require complex electronics for biasing and amplification and rely on materials that offer limited sensor selectivity and sensitivity. These restrictions result in bulky, tethered, or battery-powered systems impacting behavior and that require constant care of subjects. To overcome these challenges, we demonstrate a fully implantable, wireless, and battery-free platform that enables optogenetic stimulation and electrochemical recording of catecholamine dynamics in real time. The device is nearly 1/10th the size of previously reported examples and includes a probe that relies on a multilayer electrode architecture featuring a microscale light emitting diode (μ-LED) and a carbon nanotube (CNT)-based sensor with sensitivities among the highest recorded in the literature (1264.1 nA μM-1 cm-2). High sensitivity of the probe combined with a center tapped antenna design enables the realization of miniaturized, low power circuits suitable for subdermal implantation even in small animal models such as mice. A series of in vitro and in vivo experiments highlight the sensitivity and selectivity of the platform and demonstrate its capabilities in freely moving, untethered subjects. Specifically, a demonstration of changes in dopamine concentration after optogenetic stimulation of the nucleus accumbens and real-time readout of dopamine levels after opioid and naloxone exposure in freely behaving subjects highlight the experimental paradigms enabled by the platform.Fil: Stuart, Tucker. University of Arizona; Estados UnidosFil: Jeang, William J.. Northwestern University; Estados UnidosFil: Slivicki, Richard A.. University of Washington; Estados UnidosFil: Brown, Bobbie J.. University of Washington; Estados UnidosFil: Burton, Alex. University of Arizona; Estados UnidosFil: Brings, Victoria E.. University of Washington; Estados UnidosFil: Agyare, Prophecy. Northwestern University; Estados UnidosFil: Alarcon Segovia, Lilian Celeste. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Matemática Aplicada del Litoral. Universidad Nacional del Litoral. Instituto de Matemática Aplicada del Litoral; ArgentinaFil: Ruiz, Savanna. Northwestern University; Estados UnidosFil: Tyree, Amanda. University of Arizona; Estados UnidosFil: Pruitt, Lindsay. University of Arizona; Estados UnidosFil: Madhvapathy, Surabhi. Northwestern University; Estados UnidosFil: Niemiec, Martin. University of Arizona; Estados UnidosFil: Zhuang, James. University of Arizona; Estados UnidosFil: Krishnan, Siddharth. Northwestern University; Estados UnidosFil: Copits, Bryan A.. University of Washington; Estados UnidosFil: Rogers, John A.. Northwestern University; Estados UnidosFil: Gereau, Robert W.. Washington University in St. Louis; Estados UnidosFil: Samineni, Vijay K.. University of Washington; Estados UnidosFil: Bandodkar, Amay J.. No especifíca;Fil: Gutruf, Philipp. University of Arizona; Estados Unido

    Oral administration of an HSP90 inhibitor, 17-DMAG, intervenes tumor-cell infiltration into multiple organs and improves survival period for ATL model mice

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    In the peripheral blood leukocytes (PBLs) from the carriers of the human T-lymphotropic virus type-1 (HTLV-1) or the patients with adult T-cell leukemia (ATL), nuclear factor kappaB (NF-κB)-mediated antiapoptotic signals are constitutively activated primarily by the HTLV-1-encoded oncoprotein Tax. Tax interacts with the I κB kinase regulatory subunit NEMO (NF-κB essential modulator) to activate NF-κB, and this interaction is maintained in part by a molecular chaperone, heat-shock protein 90 (HSP90), and its co-chaperone cell division cycle 37 (CDC37). The antibiotic geldanamycin (GA) inhibits HSP90\u27s ATP binding for its proper interaction with client proteins. Administration of a novel water-soluble and less toxic GA derivative, 17-dimethylaminoethylamino-17-demethoxygeldanamycin hydrochloride (17-DMAG), to Tax-expressing ATL-transformed cell lines, C8166 and MT4, induced significant degradation of Tax. 17-DMAG also facilitated growth arrest and cellular apoptosis to C8166 and MT4 and other ATL cell lines, although this treatment has no apparent effects on normal PBLs. 17-DMAG also downregulated Tax-mediated intracellular signals including the activation of NF-κB, activator protein 1 or HTLV-1 long terminal repeat in Tax-transfected HEK293 cells. Oral administration of 17-DMAG to ATL model mice xenografted with lymphomatous transgenic Lck-Tax (Lck proximal promoter-driven Tax transgene) cells or HTLV-1-producing tumor cells dramatically attenuated aggressive infiltration into multiple organs, inhibited de novo viral production and improved survival period. These observations identified 17-DMAG as a promising candidate for the prevention of ATL progression
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